We will continue HSV-1 mRNA mapping studies in order to complete our description of size, location, in vitro translation products, and temporal class of the major viral mRNAs mapping in the HSV genome. The above data, as well as nucleotide sequence analysis described elsewhere, will lead us to define typical early (Beta) and late (Beta Lambda and Lambda) "promoters." We will continue our analysis by examining the products of transcription of moDel HSV-1 genes. We will use in vitro systems from infected and uninfected cells. We also will introduce prototypical HSV-1 genes into cells using one of several methods recently described by others. Once these are introduced, we will be able to determine the effect of viral superinfection on the expression of classes of HSV-1 genes. We will manipulate the sequences of the promoter regions to confirm their role in the control of viral gene expression. We will investigate the biological function of specific HSV-1 genes identified above. We pose two avenues of attack: (a) collaboration with Professors G. Cohen and R. Eisenberg of the University of Pennsylvania to use their collection of poly- and monospecific antisera against viral structural proteins to investigate specific in vitro translation products; (b) collaboration with Professor J. Stevens of the University of California, Los Angeles, in his marker rescue studies to attempt to identify specific viral genes involved in different aspect of HSV pathology.